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Technology: Eggsat technique

There would probably be fewer Easter eggs to tuck into this weekend
if it were not for the skills of a photographer.

Eggs are made by machines which flick ‘waves’ of molten chocolate over
rows of cooled metal moulds. The machines work at high speed, and need to
be synchronised accurately.

Unfortunately, if the machines are slowed down so that the operator
can see what is happening, they cannot be synchronised correctly for full
speed operation.

John Rendell, a high-speed photography expert, was called in by a well-known
chocolate factory to video its Easter egg and bubble-filled chocolate bar
machines. He took black and white videos at 1000 frames per second, and
the problems were revealed by viewing the video in slow motion. ‘Every production
line I know is the same – cigarettes, tablets and so on,’ he says. With
proper tuning most machines can go 10 to 15 per cent faster, he estimates.